Ratchet means



June 28, 1949. M. A. NAPIER RATCHET MEANS Filed July 12, 1945 mm mm. W

raven-rota MAURICE: A. NAPIER av I Patented June 28, 1949 Nzl'l' soSTATES PATENT orrlce- RATCHET Maurice A. Napier, Akron, Ohio ApplicationJuly-1 1945, Serial No. 604,605.,

'7 Claims.

1. This. invention relates to wrenches, and more especially. it relatesto improved ratchet wrenches.

The chief objects of, the invention are to providein animproved mannerfor ease and facility.

cf ,mountin-g and dismounting the head of the wrench; to provide aratchet wrench wherein the head isreversible in the handle or leverportion thereof, whereby the utility ofthe wrench is enhanced; andtoprovide a wrench ofthe character mentioned that will have relatively fewoperative parts. More specifically the invention aims to provide aratchet; wrench that is of simple con struction, that is strong and.durable, that may operate in ituations difficult of access, and whichmay be manufactured at relatively low cost. Other objects will. bemanifest asthe description proceeds.

f the accompanying drawing:

Fig. 1 is aside elevation of a ratchet wrench m o neth n n n;

Fig. 2 is a plan view, thereof Fig. 3 is an end, elevation of the wrenchas viewedfroin theleft of Fig. 2

Fisa agmen ary p nvi w f h p ra..-

tive end of the wrench, a. Pm?! thereof being broken away and in sectionto reveal underlying.

structure;

Fig, 5 is a section on the line 5-5 of Fig. 4,

mounted-on respective pivot pins I3 carried bysaid handle or lever, andengageable with said head, and spring elements I land I5 mounted uponthe handle or lever I0 by means of screws I6, said springs-engagingrespective pawls.

The rotatable head I I is shown, for illustrative purposes only, as abox type of wrench that has two sockets; indicated at I8, I9, whichsocketsare 'coaxially arranged at apposite ends of j the head;

and are of different-sizes so as to engage two different sizes ofn-utsorbolts. It will be understood, however, that the head His not-limited tothe box or socket type of wrench formation, but may be of any other typeof tool-turning structure, for example; a chuck for a drill bit.Exteriorly, the head II isformed with a circumferential-series ofratchet teeth which-preferably, though not necessarily, are locatedcentrallyof the-head, midway betweentheendsthereof:

The teeth 2!) are symmetrical; that is, the op-. posite, pawl-engagingfaces 2I, 22-thereof are. o

thesame size andslope so that, the headmay be assembled with the handleor lever with either side constituting the top thereof, for thepurposeof utilizingeither socket It or I9, or for the purpose of"turning the head in a particular direc-. tion when the handle I0 isoscillated. Each of the lateral, or end faces 23 of the teeth 20 are;

flat, said faces tapering or inclin ng somewhat toward, each other,asshown in Figs. 1 and 3y,

fromthe roots of, the teeth to the crowns theresomewhat toward theadjacent ends thereof.

The handleorlever Ill is an elongate structure adapted to be grasped byan operator at one end" thereof, its. other endbeing arranged to receivethe. head II. To this end the said handle or lever is, formedjat, itsoperating endwith a head-.-

' receiving recess, a portionof which constitutes an arc of extent. Theaxis of said are is;

on the. centerline lithe handle but the recess is not necessarilysymmetrical with the handle, but.

may be asymmetrically arrangedas shown. The

arcuate portion of the recess isthat portion there-,. of that. islocated to the right of line aa, Fig. 2, At...

saidline extending. diametrically of the, arc. each endof said arc, tothe left of,1inea-a, the

recess is slightly flared orwidened, the surface. thereotmerginawithsurfaces 26,, 26 of the handle,

structure at oppositesides of the recess.

As is best shown in Fig.5, the configuration. of the hcadrreceivingrecess is such as to providev apair of concentric concave bearingsurfaces 28, ,8 that are separated .by a groove 25!.

received in the groove 29. The latter is deeper than the height oftheteeth 20 so that the crowns thereof do not touch the-bottom of thegroove.

The lateral walls of the groove, however, are

tapered toward; the bottom thereof, which taper is oomplementalto thetaper of the lateral faces. of said teeth. Preferably there isslightclear-. ance betweenthe lateral walls of the groove 29;

and the-latera-ifaces of the teeth 29 so that there is but a modicum offriction therebetween. The

The radius. of the bearingsurfacesiBv is the same asthera dius of thetrunnions 2.4.of. the head II, said. trunnions seating upon thevrespective bearing; surfaces, in the operative conditionof the wrench.andtheperipheral teeth 20, of the head being-.

3 arrangement is such as to facilitate the mounting of the head II inthe handle it, and to restrain relative axial movement between head andhandle.

Those portions of the handle I!) that are located at opposite sides ofthe open end of the head-receiving recess are slotted at 32, 33,parallel to the plane of the head between opposite faces thereof, a pawll2 being located in each of said slots. As is most clearly shown in Fig.4, each pawl l2 has a profile formed of two flat sides and a curvedside, said flat sides meeting at an obtuse angle that constitutes a noseportion adapted to enter the notches between adjacent teeth 26 for thepurpose of operatively engaging the teeth. The curved side of each pawlmay be and preferably is the arc of a circle, and the axis of said areis eccentrically disposed with relation to the pivot point of the pawlon the pin l3. The pawl [2 that is located in slot 32 is urged intoengagement with the teeth 20 by the flat leaf spring l4 that overliessaid slot and engages the arcuate surface of said pawl. In like mannerthe arcuate leaf spring 55 overlies the slot 33 and engages the arcuatesurface of pawl l2 therein.

The pawls l2 are reversely arranged so that both operatively engage theteeth 29, when the lever it is turned in counterclockwise direction,there-by to effect turning of the head i I. When the lever it is turnedin clockwise direction, the pawls ratchet over the teeth 20, beinglifted by the latter against the force of the springs [4, I5. Thisresult is achieved by reason of the fact that the pivot pins l3 of thepawls are so eccentrically disposed with relation to the respective axesof the curved surfaces of the pawls l2, that in the lifting of thelatter the surface areas of the pawls that progressively move intoengagement with the springs i4, I5 are progressively more remote fromthe respective pivot pins.

The pawls 12 are arranged to engage the head l l at exactlydiametrically opposite points, which points are at opposite ends of thearcuate region of the lever-recess in which said head is located, aswill be seen by reference to line a--a of Fig. 1. The arrangement issuch that stresses incidental to operation of the wrench are distributedbetween two widely separated regions of the lever [0, whereby it ispossible to employ the wrench for relatively heavy work without dangerof breakage to the wrench. The head H cannot be removed from the lever[0 by direct pull in the direction normal to line aa, but requires, inaddition, concurrent relative rotary movement of head and lever wherebythe head will pivot about one pawl l2 as it is pulled past the otherpawl against the force of spring Id. The operation is reversed when thehead is to be mounted in the lever, at which time the teeth 26] arepushed past pawl l2 against the force of spring I5, while turningpivotally about the other pawl I2. Both in dismounting and remountingthe head i l, the relative movement between head and handle is all inplane of the wrench structure, that is, transversely of the axis ofrotation of the head.

The embodiment of the invention shown in Fig. 6 is somewhat similar tothe embodiment previously described, and in some respects is identicalthereto. Thus the ratchet head I! is the same head that is employed inthe previously described embodiment. The handle or lever Illa is similarto the lever [0 in that it is formed with an arcuate recess 36 of 180extent in which the head ll is received and wherein it is adapted torotate relatively of the lever. The embodiment of the invention shown inFig. 6 differs from that previously described in that the pivotallymounted pawls l2 are omitted, and a single spring-pressed detent 31 isemployed, which detent is located at one end of the arcuate recess 36 inwhich the head is mounted. Said detent is of general cylindrical shapeand is monnted for axial movement in a bore 38 in the lever structurelfla, an arcuate leaf spring 33 on the latter engaging the outer end ofthe detent and urging it toward the teeth 20 of the head. The inner endof the detent 37' is formed with a nose portion 31a composed of two flatsurfaces meeting at an angle that is complemental to the angle of thenotch between two adjacent ratchet teeth 20, the plane of one of theflat surfaces of said nose portion being parallel to the axis of thedetent, as shown. The detent 31 is disposed in non-radial relation tothe head H, the nose portion of the detent being adapted to engage in anotch between two ratchet teeth 29, the arrangement being such that whenthe head Ii is held stationary and the lever ltd turned incounter-clockwise direction, as viewed in Fig. 6, the detent 37 will beforced outwardly, against the force of the spring 39, and thus enabledto ratchet over the teeth 20; when the lever is turned in clockwisedirection, the detent is subjected to lateral stress, and crampedbetween a.

tooth 2!} and the bore 38 in which it is mounted. This preventsregressive movement of the detent, and the head II is caused to turnwith the lever Ma. The head ii is yieldingly retained in the recess 36of the lever I90. by a bifurcated leaf spring 49 that is secured to thelever at a point substantially diametrically opposite the detent 31, andwhich engages the respective trunnions 24 of the head, tangentiallythereof, at a point substantially beyond the adjacent end of the recess36 in which the head is seated. Thus the head and lever are maintainedin operative association when desired, but readily are separated by apulling and turning movement, against the force of spring 40, whendesired. The operation is reversed when it is desired to mount the headin the lever. The modified embodiment of the invention retainssubstantially all of the advantageous features of the embodiment firstdescribed, but is intended for lighter work than the latter for thereason that stresses are localized in the region of the detent 31.

The invention provides an improved ratchet wrench in which differentsizes and/or types of heads readily are employed. The heads are readilymountable and dismountable in the lever without requiring the use ofother tools. The feature of employing a tapered groove for receivingratchet teeth having complementally sloped lateral faces facilitatescentering of the head during the mounting thereof. The wrench hasrelatively few parts and is economically produced, and achieves theother advantages set out in the foregoing statement of objects.

Modification may be resorted to; without departing from the spirit ofthe invention or the scope thereof as defined by the appended claims.

What is claimed is:

1. In a ratchet wrench the combination of a lever, and a head removablymounted on one end thereof, said head formed circumferentially withratchet teeth having end faces that taper toward each other, and withtrunnions at each side of the ratchet teeth. said lever formed with arecess of 180 extent in which said head is receivable, which recesscomprises a groove having sides tapered complemental to the ratchetteeth and adapted loosely to contact the latter, there being bearingsurfaces each side of said groove on which the trunnions of the head areseated, and ratchet means carried by the lever at relatively widelyspaced points and engaging said ratchet teeth on the head for turningthe latter when the lever is turned in one direction, said ratcht meansincluding spring mechanism adapted normally to retain said head in saidlever-recess, and being yielding so as to enable both dismounting andremounting of the head by relative movement of head and lever in theplane of the wrench structure.

2. A combination as defined in claim 1 whereof the ratchet meansconsists of two pivotally mounted spring-backed pawls that engage theratchet teeth 180 apart.

3. A combination as defined in claim 1 whereof the ratchet meanscomprises a pair of pivotally mounted pawls each having an arcuatemarginal face that is arranged eccentrically of its pivot, and springmeans bearing against the arcuate faces of said pawls.

4. A combination as defined in claim 1 whereof the ratchet teeth on thehead have oppositefaces of equal size and slope, the ratchet meanscomprising a spring-pressed detent disposed nonradially of the head andhaving a nose shaped complemental to a notch between two adjacentratchet teeth, the plane of one of the faces of said nose being parallelto the axis of the detent.

5. In a ratchet wrench of the character described, the combination of alever, and a head removably mounted on one end thereof, said head formedcircumferentially with ratchet teeth that have opposite faces of equalsize and slope, and with trunnions at each side of said ratchet teeth,said lever formed with a recess of extent in which said head isreceivable, which recess comprises a groove for receiving said teeth,there being bearing surfaces each side of said groove on which thetrunnions of the head are journaled, a spring-pressed detent carried bythe lever at one end of said lever-recess and engaging said ratchetteeth, said detent being movable non-radially of said head, and springmeans carried by the lever and engaging said head, beyond the other endof said recess, to retain the head yieldingly therein.

6. A combination as defined in claim 5 whereof the detent is formed witha nose portion shaped complemental to a notch between two ratchet teeth,the plane of one of the faces of said nose portion being parallel to theaxis of the detent.

7 A combination as defined in claim 5 whereof the last mentioned springmeans is a bifurcated leaf spring that bears against the respectivetrunnions of the head.

MAURICE A. NAPIER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 326,876 Kramer et al. Sept. 22,1885 733,185 Grady July 7, 1903 834,219 Young Oct. 23, 1906 1,119,292Lawson Dec. 1, 1914 1,431,064 Triesch Oct. 3, 1922 1,733,012 HendersonOct. 22, 1929 1,827,202 Klein Oct. 13, 1931 1,902,878 McNaught et a1.Mar. 28, 1933 2,358,362 Taylor Sept. 19, 1944. 2,401,128 Anderson May28, 1946

